Its all unconfirmed, just repeating what a family told me one evening when the topic came up.
I did visit the Mayan Pyramids in HueHuetenango Guatemala two weeks ago though.
It is true you cannot climb the original stairs on the temples (I heard it was due to tourists slipping and falling) but when I was there 4 years ago there were wooden stars built on the side of the temple you can climb to the top.